| Andrew Scull | b4b6d4a | 2019-01-02 15:54:55 +0000 | [diff] [blame] | 1 | /* SPDX-License-Identifier: GPL-2.0 */ |
| 2 | /* |
| 3 | * Only give sleepers 50% of their service deficit. This allows |
| 4 | * them to run sooner, but does not allow tons of sleepers to |
| 5 | * rip the spread apart. |
| 6 | */ |
| 7 | SCHED_FEAT(GENTLE_FAIR_SLEEPERS, true) |
| 8 | |
| 9 | /* |
| 10 | * Place new tasks ahead so that they do not starve already running |
| 11 | * tasks |
| 12 | */ |
| 13 | SCHED_FEAT(START_DEBIT, true) |
| 14 | |
| 15 | /* |
| 16 | * Prefer to schedule the task we woke last (assuming it failed |
| 17 | * wakeup-preemption), since its likely going to consume data we |
| 18 | * touched, increases cache locality. |
| 19 | */ |
| 20 | SCHED_FEAT(NEXT_BUDDY, false) |
| 21 | |
| 22 | /* |
| 23 | * Prefer to schedule the task that ran last (when we did |
| 24 | * wake-preempt) as that likely will touch the same data, increases |
| 25 | * cache locality. |
| 26 | */ |
| 27 | SCHED_FEAT(LAST_BUDDY, true) |
| 28 | |
| 29 | /* |
| 30 | * Consider buddies to be cache hot, decreases the likelyness of a |
| 31 | * cache buddy being migrated away, increases cache locality. |
| 32 | */ |
| 33 | SCHED_FEAT(CACHE_HOT_BUDDY, true) |
| 34 | |
| 35 | /* |
| 36 | * Allow wakeup-time preemption of the current task: |
| 37 | */ |
| 38 | SCHED_FEAT(WAKEUP_PREEMPTION, true) |
| 39 | |
| 40 | SCHED_FEAT(HRTICK, false) |
| 41 | SCHED_FEAT(DOUBLE_TICK, false) |
| Andrew Scull | b4b6d4a | 2019-01-02 15:54:55 +0000 | [diff] [blame] | 42 | |
| 43 | /* |
| 44 | * Decrement CPU capacity based on time not spent running tasks |
| 45 | */ |
| 46 | SCHED_FEAT(NONTASK_CAPACITY, true) |
| 47 | |
| 48 | /* |
| 49 | * Queue remote wakeups on the target CPU and process them |
| 50 | * using the scheduler IPI. Reduces rq->lock contention/bounces. |
| 51 | */ |
| 52 | SCHED_FEAT(TTWU_QUEUE, true) |
| 53 | |
| 54 | /* |
| 55 | * When doing wakeups, attempt to limit superfluous scans of the LLC domain. |
| 56 | */ |
| 57 | SCHED_FEAT(SIS_AVG_CPU, false) |
| 58 | SCHED_FEAT(SIS_PROP, true) |
| 59 | |
| 60 | /* |
| 61 | * Issue a WARN when we do multiple update_rq_clock() calls |
| 62 | * in a single rq->lock section. Default disabled because the |
| 63 | * annotations are not complete. |
| 64 | */ |
| 65 | SCHED_FEAT(WARN_DOUBLE_CLOCK, false) |
| 66 | |
| 67 | #ifdef HAVE_RT_PUSH_IPI |
| 68 | /* |
| 69 | * In order to avoid a thundering herd attack of CPUs that are |
| 70 | * lowering their priorities at the same time, and there being |
| 71 | * a single CPU that has an RT task that can migrate and is waiting |
| 72 | * to run, where the other CPUs will try to take that CPUs |
| 73 | * rq lock and possibly create a large contention, sending an |
| 74 | * IPI to that CPU and let that CPU push the RT task to where |
| 75 | * it should go may be a better scenario. |
| 76 | */ |
| 77 | SCHED_FEAT(RT_PUSH_IPI, true) |
| 78 | #endif |
| 79 | |
| Olivier Deprez | 157378f | 2022-04-04 15:47:50 +0200 | [diff] [blame^] | 80 | SCHED_FEAT(RT_RUNTIME_SHARE, false) |
| Andrew Scull | b4b6d4a | 2019-01-02 15:54:55 +0000 | [diff] [blame] | 81 | SCHED_FEAT(LB_MIN, false) |
| 82 | SCHED_FEAT(ATTACH_AGE_LOAD, true) |
| 83 | |
| 84 | SCHED_FEAT(WA_IDLE, true) |
| 85 | SCHED_FEAT(WA_WEIGHT, true) |
| 86 | SCHED_FEAT(WA_BIAS, true) |
| 87 | |
| 88 | /* |
| 89 | * UtilEstimation. Use estimated CPU utilization. |
| 90 | */ |
| 91 | SCHED_FEAT(UTIL_EST, true) |
| Olivier Deprez | 157378f | 2022-04-04 15:47:50 +0200 | [diff] [blame^] | 92 | SCHED_FEAT(UTIL_EST_FASTUP, true) |
| 93 | |
| 94 | SCHED_FEAT(ALT_PERIOD, true) |
| 95 | SCHED_FEAT(BASE_SLICE, true) |